   (let [train-data (filter-attribute-data train-data attributes)
         test-data (->> (filter-attribute-data test-data attributes)
                        weka/clone-instances)
+        _ (log/infof "testing on %d instances" (.numInstances test-data))
         eval (Evaluation. train-data)]
     (.evaluateModel eval classifier test-data zero-arg-arr)
     eval))

             (.getName (.getClass classifier))
             (str/join ", " attributes))
  (let [raw-data (get-data)
        train-data (filter-attribute-data raw-data attributes)]
    (.buildClassifier classifier train-data)
    classifier))

             (.getName (.getClass classifier))
             (str/join ", " attributes))
  (let [data (get-data)
        _ (log/infof "cross validate on %d instances" (.numInstances data))
        {:keys [eval attribs train-total] :as cve}
        (cross-validate-evaluation classifier data attributes)]
    (merge (select-keys cve [train-total])
